Fats are an important part of our diet; they provide the body with energy and with some important vitamins (for example, vitamins A and D). They also contain essential fats which the body is unable to make for itself. However, eating too much fat can be unhealthy. The consumption of saturated fats may be associated with increased blood cholesterol levels which may result in coronary heart disease, for example.
Current UK government guidelines advise cutting down on all fats and replacing saturated fat with some unsaturated fat. Many consumers try to reduce fat intake, but they are more likely to succeed if reduced fat food products are available which provide the same eating pleasure as their full-fat equivalents.
It is challenging to reduce the fat content of food without altering its essential sensory character, such as flavour, mouthfeel, and aroma. Food which are lipid-in-water emulsions present particular challenges. Such emulsions are common in food, being present in foods such as mayonnaise, salad dressings, sauces, and milk. One approach to reduce the fat content in products such as mayonnaise is to remove the fat completely and add texture modifying ingredients to the mayonnaise to try and simulate the mouthfeel generated by fat. However, the texture difference is often apparent to the consumer, and the ingredients used to modify the texture may be food additives that the consumers prefers not to eat.
Providing fat in the form of a foam provides a method to maintain product volume whilst reducing the fat content. However, the major difficulty in generating stable foam structures within lipid-based systems as compared to water-based systems lies in the lack of suitable surfactants for forming stable interfaces between air and lipid. Those surfactants which have been proposed may not be suitable for stabilizing edible foams due to toxicity or unpleasant taste. As a consequence, the most common approach for obtaining stable foams in fats is by forming a rigid network in the bulk material, for example by forming a rigid network of crystals in a liquid lipid continuous phase or by rapidly cooling the lipid so as to solidify the bulk material.
In the case of food products based on lipid-in-water emulsions, stabilizing the fat foam by solidification or by forming a rigid network in the bulk material would cause a significant change in texture. Lipid-in-water emulsions also present a major technical problem in that any fat foam must be stable enough to survive being emulsified into the aqueous phase. Having a rigid network in the bulk liquid fat material affects the ability of the foam to be pumped, deposited, or mixed with other components without destroying the stabilizing network leading to coalescence of bubbles.
Hence, there is a need in industry to provide reduced-fat food compositions based on lipid-in-water emulsions, in particular edible emulsions which taste good and are made from natural ingredients. An object of the present invention is to improve the state of the art and to provide an improved solution to overcome at least some of the inconveniences described above or at least to provide a useful alternative. Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field. As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to”. The object of the present invention is achieved by the subject matter of the independent claims. The dependent claims further develop the idea of the present invention.